Scottish actor James McAvoy found his boss Robert Redford a tough taskmaster while working on the star's latest movie - after the Hollywood veteran ordered him to speak in an American accent at all times.The Last King of Scotland star is playing U.S. lawyer Frederick Aiken in Redford's The Conspirator, about the trial of a woman said to be involved in the assassination of 19th century American president Abraham Lincoln. But MCAvoy found himself at work even when the cameras stopped rolling - because Redford demanded he kept his U.S. lilt even during his downtime. He says, "Bob wants me to stay in an American accent all the time. I'm trying to but I just can't be bothered all the time. I'm trying to make Bob happy, but that's an exhausting task. "I'll get there eventually, hopefully, one day. So, no, I'm not particularly method with either my accents or my acting."